Elara Bennett1 lux equals 1 lumen per square meter. So, converting 1 lux to lumens depends on the area illuminated. For example, over 1 square meter, 1 lux corresponds to 1 lumen.
Lux measures illuminance, which is lumens spread over an area. Lumens quantify total light output, while lux accounts for how that light is distributed per square meter. Therefore, to convert lux to lumens, multiply by the surface area in square meters.
Conversion Tool
Result in lumens:
Conversion Formula
The formula to convert lux (lx) to lumens (lm) involves multiplying the lux value by the area in square meters. Mathematically, it is:
Lumens (lm) = Lux (lx) × Area (m²)
This works because lux measures the light intensity per unit area, while lumens measure total light output. So, if you know the lux level over a certain surface, multiplying by the surface’s size gives the total lumens hitting that area.
For example, if 1 lux shines over 2 m²:
- Calculate: 1 lx × 2 m² = 2 lm
- Result: 2 lumens total light output over that area
Conversion Example
- 5 lux over 3 m²:
- Multiply 5 lx × 3 m²
- Result: 15 lumens
- 10 lux over 0.5 m²:
- Calculate 10 lx × 0.5 m²
- Result: 5 lumens
- 0.2 lux over 10 m²:
- Multiply 0.2 lx × 10 m²
- Result: 2 lumens
- 100 lux over 0.1 m²:
- Calculate 100 lx × 0.1 m²
- Result: 10 lumens
- 7.5 lux over 4 m²:
- Multiply 7.5 lx × 4 m²
- Result: 30 lumens
Conversion Chart
The chart below shows lux values from -24.0 to 26.0 and their equivalent in lumens assuming an area of 1 square meter. Negative lux values are non-physical but included here for completeness.
| Lux (lx) | Lumens (lm) |
|---|---|
| -24.0 | -24.0 |
| -18.0 | -18.0 |
| -12.0 | -12.0 |
| -6.0 | -6.0 |
| 0.0 | 0.0 |
| 6.0 | 6.0 |
| 12.0 | 12.0 |
| 18.0 | 18.0 |
| 24.0 | 24.0 |
| 26.0 | 26.0 |
This chart can used to quickly find lumens when you know lux and area is 1 m². Multiply lux by area if different area is involved.
Related Conversion Questions
- How many lumens correspond to 1 lux on a 1 square meter surface?
- What is the lumens output for 1 lux lighting in a room?
- Can 1 lux be converted directly to lumens without knowing area?
- How to calculate lumens from 1 lux if area is 2 square meters?
- Does 1 lux equal 1 lumen for all lighting conditions?
- Is there a formula to convert 1 lux to lumens for different surface sizes?
- Why does converting 1 lux to lumens require area information?
Conversion Definitions
Lux: Lux is a unit measuring illuminance, expressing how much luminous flux falls on a surface per square meter. It quantifies the intensity of light hitting an area, helping to gauge brightness for environments, workplaces, or photography.
Lumens: Lumens measure total visible light emitted by a source. It quantifies brightness independent of direction or distance, showing how much light a bulb or fixture produces, useful for comparing lighting output.
Conversion FAQs
Why does converting lux to lumens need area value?
Because lux measure light intensity per area, without knowing how big the surface is, you cannot find total lumens. Lumens are total light output, so multiplying lux by area gives actual lumens hitting that surface.
Can I assume 1 lux equals 1 lumen?
No, 1 lux equals 1 lumen only if the area illuminated is exactly 1 square meter. If area varies, lumens change proportionally, so direct equivalence without area is incorrect.
Is it possible to convert lumens to lux?
Yes, lux can be found from lumens by dividing lumens by surface area in square meters. This reverses the conversion, giving light intensity for given total lumens and area.
What happens if area is zero or unknown?
Conversion cannot be done if area is zero or unknown, since lux relates lumens over area. Without area, lumens cannot be calculated accurately from lux values.
Are lux and lumens measured with same instruments?
No, lux meters measure illuminance on surfaces. Lumens are often calculated from light source specifications or using integrating spheres. Different tools measure each quantity due to their nature.
